kern_linker.c revision 159845
1/*- 2 * Copyright (c) 1997-2000 Doug Rabson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: head/sys/kern/kern_linker.c 159845 2006-06-21 20:42:08Z jhb $"); 29 30#include "opt_ddb.h" 31#include "opt_hwpmc_hooks.h" 32#include "opt_mac.h" 33 34#include <sys/param.h> 35#include <sys/kernel.h> 36#include <sys/systm.h> 37#include <sys/malloc.h> 38#include <sys/sysproto.h> 39#include <sys/sysent.h> 40#include <sys/proc.h> 41#include <sys/lock.h> 42#include <sys/mutex.h> 43#include <sys/sx.h> 44#include <sys/mac.h> 45#include <sys/module.h> 46#include <sys/mount.h> 47#include <sys/linker.h> 48#include <sys/fcntl.h> 49#include <sys/libkern.h> 50#include <sys/namei.h> 51#include <sys/vnode.h> 52#include <sys/syscallsubr.h> 53#include <sys/sysctl.h> 54 55#include "linker_if.h" 56 57#ifdef HWPMC_HOOKS 58#include <sys/pmckern.h> 59#endif 60 61#ifdef KLD_DEBUG 62int kld_debug = 0; 63#endif 64 65#define KLD_LOCK() do { sx_xlock(&kld_sx); mtx_lock(&Giant); } while (0) 66#define KLD_UNLOCK() do { mtx_unlock(&Giant); sx_xunlock(&kld_sx); } while (0) 67#define KLD_LOCKED() sx_xlocked(&kld_sx) 68#define KLD_LOCK_ASSERT() do { if (!cold) sx_assert(&kld_sx, SX_XLOCKED); } while (0) 69 70/* 71 * static char *linker_search_path(const char *name, struct mod_depend 72 * *verinfo); 73 */ 74static const char *linker_basename(const char *path); 75 76/* 77 * Find a currently loaded file given its filename. 78 */ 79static linker_file_t linker_find_file_by_name(const char* _filename); 80 81/* 82 * Find a currently loaded file given its file id. 83 */ 84static linker_file_t linker_find_file_by_id(int _fileid); 85 86/* Metadata from the static kernel */ 87SET_DECLARE(modmetadata_set, struct mod_metadata); 88 89MALLOC_DEFINE(M_LINKER, "linker", "kernel linker"); 90 91linker_file_t linker_kernel_file; 92 93static struct sx kld_sx; /* kernel linker lock */ 94 95static linker_class_list_t classes; 96static linker_file_list_t linker_files; 97static int next_file_id = 1; 98static int linker_no_more_classes = 0; 99 100#define LINKER_GET_NEXT_FILE_ID(a) do { \ 101 linker_file_t lftmp; \ 102 \ 103 KLD_LOCK_ASSERT(); \ 104retry: \ 105 TAILQ_FOREACH(lftmp, &linker_files, link) { \ 106 if (next_file_id == lftmp->id) { \ 107 next_file_id++; \ 108 goto retry; \ 109 } \ 110 } \ 111 (a) = next_file_id; \ 112} while(0) 113 114 115/* XXX wrong name; we're looking at version provision tags here, not modules */ 116typedef TAILQ_HEAD(, modlist) modlisthead_t; 117struct modlist { 118 TAILQ_ENTRY(modlist) link; /* chain together all modules */ 119 linker_file_t container; 120 const char *name; 121 int version; 122}; 123typedef struct modlist *modlist_t; 124static modlisthead_t found_modules; 125 126static int linker_file_add_dependency(linker_file_t file, 127 linker_file_t dep); 128static caddr_t linker_file_lookup_symbol_internal(linker_file_t file, 129 const char* name, int deps); 130static int linker_load_module(const char *kldname, 131 const char *modname, struct linker_file *parent, 132 struct mod_depend *verinfo, struct linker_file **lfpp); 133static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo); 134 135static char * 136linker_strdup(const char *str) 137{ 138 char *result; 139 140 if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL) 141 strcpy(result, str); 142 return (result); 143} 144 145static void 146linker_init(void *arg) 147{ 148 149 sx_init(&kld_sx, "kernel linker"); 150 TAILQ_INIT(&classes); 151 TAILQ_INIT(&linker_files); 152} 153 154SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0) 155 156static void 157linker_stop_class_add(void *arg) 158{ 159 160 linker_no_more_classes = 1; 161} 162 163SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL) 164 165int 166linker_add_class(linker_class_t lc) 167{ 168 169 /* 170 * We disallow any class registration past SI_ORDER_ANY 171 * of SI_SUB_KLD. We bump the reference count to keep the 172 * ops from being freed. 173 */ 174 if (linker_no_more_classes == 1) 175 return (EPERM); 176 kobj_class_compile((kobj_class_t) lc); 177 ((kobj_class_t)lc)->refs++; /* XXX: kobj_mtx */ 178 TAILQ_INSERT_TAIL(&classes, lc, link); 179 return (0); 180} 181 182static void 183linker_file_sysinit(linker_file_t lf) 184{ 185 struct sysinit **start, **stop, **sipp, **xipp, *save; 186 187 KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n", 188 lf->filename)); 189 190 if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0) 191 return; 192 /* 193 * Perform a bubble sort of the system initialization objects by 194 * their subsystem (primary key) and order (secondary key). 195 * 196 * Since some things care about execution order, this is the operation 197 * which ensures continued function. 198 */ 199 for (sipp = start; sipp < stop; sipp++) { 200 for (xipp = sipp + 1; xipp < stop; xipp++) { 201 if ((*sipp)->subsystem < (*xipp)->subsystem || 202 ((*sipp)->subsystem == (*xipp)->subsystem && 203 (*sipp)->order <= (*xipp)->order)) 204 continue; /* skip */ 205 save = *sipp; 206 *sipp = *xipp; 207 *xipp = save; 208 } 209 } 210 211 /* 212 * Traverse the (now) ordered list of system initialization tasks. 213 * Perform each task, and continue on to the next task. 214 */ 215 for (sipp = start; sipp < stop; sipp++) { 216 if ((*sipp)->subsystem == SI_SUB_DUMMY) 217 continue; /* skip dummy task(s) */ 218 219 /* Call function */ 220 (*((*sipp)->func)) ((*sipp)->udata); 221 } 222} 223 224static void 225linker_file_sysuninit(linker_file_t lf) 226{ 227 struct sysinit **start, **stop, **sipp, **xipp, *save; 228 229 KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n", 230 lf->filename)); 231 232 if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop, 233 NULL) != 0) 234 return; 235 236 /* 237 * Perform a reverse bubble sort of the system initialization objects 238 * by their subsystem (primary key) and order (secondary key). 239 * 240 * Since some things care about execution order, this is the operation 241 * which ensures continued function. 242 */ 243 for (sipp = start; sipp < stop; sipp++) { 244 for (xipp = sipp + 1; xipp < stop; xipp++) { 245 if ((*sipp)->subsystem > (*xipp)->subsystem || 246 ((*sipp)->subsystem == (*xipp)->subsystem && 247 (*sipp)->order >= (*xipp)->order)) 248 continue; /* skip */ 249 save = *sipp; 250 *sipp = *xipp; 251 *xipp = save; 252 } 253 } 254 255 /* 256 * Traverse the (now) ordered list of system initialization tasks. 257 * Perform each task, and continue on to the next task. 258 */ 259 for (sipp = start; sipp < stop; sipp++) { 260 if ((*sipp)->subsystem == SI_SUB_DUMMY) 261 continue; /* skip dummy task(s) */ 262 263 /* Call function */ 264 (*((*sipp)->func)) ((*sipp)->udata); 265 } 266} 267 268static void 269linker_file_register_sysctls(linker_file_t lf) 270{ 271 struct sysctl_oid **start, **stop, **oidp; 272 273 KLD_DPF(FILE, 274 ("linker_file_register_sysctls: registering SYSCTLs for %s\n", 275 lf->filename)); 276 277 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 278 return; 279 280 mtx_lock(&Giant); 281 for (oidp = start; oidp < stop; oidp++) 282 sysctl_register_oid(*oidp); 283 mtx_unlock(&Giant); 284} 285 286static void 287linker_file_unregister_sysctls(linker_file_t lf) 288{ 289 struct sysctl_oid **start, **stop, **oidp; 290 291 KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs" 292 " for %s\n", lf->filename)); 293 294 if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0) 295 return; 296 297 mtx_lock(&Giant); 298 for (oidp = start; oidp < stop; oidp++) 299 sysctl_unregister_oid(*oidp); 300 mtx_unlock(&Giant); 301} 302 303static int 304linker_file_register_modules(linker_file_t lf) 305{ 306 struct mod_metadata **start, **stop, **mdp; 307 const moduledata_t *moddata; 308 int first_error, error; 309 310 KLD_DPF(FILE, ("linker_file_register_modules: registering modules" 311 " in %s\n", lf->filename)); 312 313 if (linker_file_lookup_set(lf, "modmetadata_set", &start, 314 &stop, NULL) != 0) { 315 /* 316 * This fallback should be unnecessary, but if we get booted 317 * from boot2 instead of loader and we are missing our 318 * metadata then we have to try the best we can. 319 */ 320 if (lf == linker_kernel_file) { 321 start = SET_BEGIN(modmetadata_set); 322 stop = SET_LIMIT(modmetadata_set); 323 } else 324 return (0); 325 } 326 first_error = 0; 327 for (mdp = start; mdp < stop; mdp++) { 328 if ((*mdp)->md_type != MDT_MODULE) 329 continue; 330 moddata = (*mdp)->md_data; 331 KLD_DPF(FILE, ("Registering module %s in %s\n", 332 moddata->name, lf->filename)); 333 error = module_register(moddata, lf); 334 if (error) { 335 printf("Module %s failed to register: %d\n", 336 moddata->name, error); 337 if (first_error == 0) 338 first_error = error; 339 } 340 } 341 return (first_error); 342} 343 344static void 345linker_init_kernel_modules(void) 346{ 347 348 linker_file_register_modules(linker_kernel_file); 349} 350 351SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules, 0) 352 353static int 354linker_load_file(const char *filename, linker_file_t *result) 355{ 356 linker_class_t lc; 357 linker_file_t lf; 358 int foundfile, error; 359 360 /* Refuse to load modules if securelevel raised */ 361 if (securelevel > 0) 362 return (EPERM); 363 364 KLD_LOCK_ASSERT(); 365 lf = linker_find_file_by_name(filename); 366 if (lf) { 367 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded," 368 " incrementing refs\n", filename)); 369 *result = lf; 370 lf->refs++; 371 return (0); 372 } 373 foundfile = 0; 374 error = 0; 375 376 /* 377 * We do not need to protect (lock) classes here because there is 378 * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY) 379 * and there is no class deregistration mechanism at this time. 380 */ 381 TAILQ_FOREACH(lc, &classes, link) { 382 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n", 383 filename)); 384 error = LINKER_LOAD_FILE(lc, filename, &lf); 385 /* 386 * If we got something other than ENOENT, then it exists but 387 * we cannot load it for some other reason. 388 */ 389 if (error != ENOENT) 390 foundfile = 1; 391 if (lf) { 392 error = linker_file_register_modules(lf); 393 if (error == EEXIST) { 394 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 395 return (error); 396 } 397 linker_file_register_sysctls(lf); 398 linker_file_sysinit(lf); 399 lf->flags |= LINKER_FILE_LINKED; 400 *result = lf; 401 return (0); 402 } 403 } 404 /* 405 * Less than ideal, but tells the user whether it failed to load or 406 * the module was not found. 407 */ 408 if (foundfile) { 409 /* 410 * Format not recognized or otherwise unloadable. 411 * When loading a module that is statically built into 412 * the kernel EEXIST percolates back up as the return 413 * value. Preserve this so that apps like sysinstall 414 * can recognize this special case and not post bogus 415 * dialog boxes. 416 */ 417 if (error != EEXIST) 418 error = ENOEXEC; 419 } else 420 error = ENOENT; /* Nothing found */ 421 return (error); 422} 423 424int 425linker_reference_module(const char *modname, struct mod_depend *verinfo, 426 linker_file_t *result) 427{ 428 modlist_t mod; 429 int error; 430 431 KLD_LOCK(); 432 if ((mod = modlist_lookup2(modname, verinfo)) != NULL) { 433 *result = mod->container; 434 (*result)->refs++; 435 KLD_UNLOCK(); 436 return (0); 437 } 438 439 error = linker_load_module(NULL, modname, NULL, verinfo, result); 440 KLD_UNLOCK(); 441 return (error); 442} 443 444int 445linker_release_module(const char *modname, struct mod_depend *verinfo, 446 linker_file_t lf) 447{ 448 modlist_t mod; 449 int error; 450 451 KLD_LOCK(); 452 if (lf == NULL) { 453 KASSERT(modname != NULL, 454 ("linker_release_module: no file or name")); 455 mod = modlist_lookup2(modname, verinfo); 456 if (mod == NULL) { 457 KLD_UNLOCK(); 458 return (ESRCH); 459 } 460 lf = mod->container; 461 } else 462 KASSERT(modname == NULL && verinfo == NULL, 463 ("linker_release_module: both file and name")); 464 error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL); 465 KLD_UNLOCK(); 466 return (error); 467} 468 469static linker_file_t 470linker_find_file_by_name(const char *filename) 471{ 472 linker_file_t lf; 473 char *koname; 474 475 koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK); 476 sprintf(koname, "%s.ko", filename); 477 478 KLD_LOCK_ASSERT(); 479 TAILQ_FOREACH(lf, &linker_files, link) { 480 if (strcmp(lf->filename, koname) == 0) 481 break; 482 if (strcmp(lf->filename, filename) == 0) 483 break; 484 } 485 free(koname, M_LINKER); 486 return (lf); 487} 488 489static linker_file_t 490linker_find_file_by_id(int fileid) 491{ 492 linker_file_t lf; 493 494 KLD_LOCK_ASSERT(); 495 TAILQ_FOREACH(lf, &linker_files, link) 496 if (lf->id == fileid) 497 break; 498 return (lf); 499} 500 501int 502linker_file_foreach(linker_predicate_t *predicate, void *context) 503{ 504 linker_file_t lf; 505 int retval = 0; 506 507 KLD_LOCK(); 508 TAILQ_FOREACH(lf, &linker_files, link) { 509 retval = predicate(lf, context); 510 if (retval != 0) 511 break; 512 } 513 KLD_UNLOCK(); 514 return (retval); 515} 516 517linker_file_t 518linker_make_file(const char *pathname, linker_class_t lc) 519{ 520 linker_file_t lf; 521 const char *filename; 522 523 KLD_LOCK_ASSERT(); 524 filename = linker_basename(pathname); 525 526 KLD_DPF(FILE, ("linker_make_file: new file, filename=%s\n", filename)); 527 lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK); 528 if (lf == NULL) 529 return (NULL); 530 lf->refs = 1; 531 lf->userrefs = 0; 532 lf->flags = 0; 533 lf->filename = linker_strdup(filename); 534 LINKER_GET_NEXT_FILE_ID(lf->id); 535 lf->ndeps = 0; 536 lf->deps = NULL; 537 STAILQ_INIT(&lf->common); 538 TAILQ_INIT(&lf->modules); 539 TAILQ_INSERT_TAIL(&linker_files, lf, link); 540 return (lf); 541} 542 543int 544linker_file_unload(linker_file_t file, int flags) 545{ 546 module_t mod, next; 547 modlist_t ml, nextml; 548 struct common_symbol *cp; 549 int error, i; 550 551 /* Refuse to unload modules if securelevel raised. */ 552 if (securelevel > 0) 553 return (EPERM); 554#ifdef MAC 555 error = mac_check_kld_unload(curthread->td_ucred); 556 if (error) 557 return (error); 558#endif 559 560 KLD_LOCK_ASSERT(); 561 KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs)); 562 563 /* Easy case of just dropping a reference. */ 564 if (file->refs > 1) { 565 file->refs--; 566 return (0); 567 } 568 569 KLD_DPF(FILE, ("linker_file_unload: file is unloading," 570 " informing modules\n")); 571 572 /* 573 * Inform any modules associated with this file. 574 */ 575 MOD_XLOCK; 576 for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) { 577 next = module_getfnext(mod); 578 MOD_XUNLOCK; 579 580 /* 581 * Give the module a chance to veto the unload. 582 */ 583 if ((error = module_unload(mod, flags)) != 0) { 584 KLD_DPF(FILE, ("linker_file_unload: module %p" 585 " vetoes unload\n", mod)); 586 return (error); 587 } 588 MOD_XLOCK; 589 module_release(mod); 590 } 591 MOD_XUNLOCK; 592 593 TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) { 594 if (ml->container == file) { 595 TAILQ_REMOVE(&found_modules, ml, link); 596 free(ml, M_LINKER); 597 } 598 } 599 600 /* 601 * Don't try to run SYSUNINITs if we are unloaded due to a 602 * link error. 603 */ 604 if (file->flags & LINKER_FILE_LINKED) { 605 linker_file_sysuninit(file); 606 linker_file_unregister_sysctls(file); 607 } 608 TAILQ_REMOVE(&linker_files, file, link); 609 610 if (file->deps) { 611 for (i = 0; i < file->ndeps; i++) 612 linker_file_unload(file->deps[i], flags); 613 free(file->deps, M_LINKER); 614 file->deps = NULL; 615 } 616 for (cp = STAILQ_FIRST(&file->common); cp; 617 cp = STAILQ_FIRST(&file->common)) { 618 STAILQ_REMOVE(&file->common, cp, common_symbol, link); 619 free(cp, M_LINKER); 620 } 621 622 LINKER_UNLOAD(file); 623 if (file->filename) { 624 free(file->filename, M_LINKER); 625 file->filename = NULL; 626 } 627 kobj_delete((kobj_t) file, M_LINKER); 628 return (0); 629} 630 631static int 632linker_file_add_dependency(linker_file_t file, linker_file_t dep) 633{ 634 linker_file_t *newdeps; 635 636 KLD_LOCK_ASSERT(); 637 newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *), 638 M_LINKER, M_WAITOK | M_ZERO); 639 if (newdeps == NULL) 640 return (ENOMEM); 641 642 if (file->deps) { 643 bcopy(file->deps, newdeps, 644 file->ndeps * sizeof(linker_file_t *)); 645 free(file->deps, M_LINKER); 646 } 647 file->deps = newdeps; 648 file->deps[file->ndeps] = dep; 649 file->ndeps++; 650 return (0); 651} 652 653/* 654 * Locate a linker set and its contents. This is a helper function to avoid 655 * linker_if.h exposure elsewhere. Note: firstp and lastp are really void **. 656 * This function is used in this file so we can avoid having lots of (void **) 657 * casts. 658 */ 659int 660linker_file_lookup_set(linker_file_t file, const char *name, 661 void *firstp, void *lastp, int *countp) 662{ 663 int error, locked; 664 665 locked = KLD_LOCKED(); 666 if (!locked) 667 KLD_LOCK(); 668 error = LINKER_LOOKUP_SET(file, name, firstp, lastp, countp); 669 if (!locked) 670 KLD_UNLOCK(); 671 return (error); 672} 673 674caddr_t 675linker_file_lookup_symbol(linker_file_t file, const char *name, int deps) 676{ 677 caddr_t sym; 678 int locked; 679 680 locked = KLD_LOCKED(); 681 if (!locked) 682 KLD_LOCK(); 683 sym = linker_file_lookup_symbol_internal(file, name, deps); 684 if (!locked) 685 KLD_UNLOCK(); 686 return (sym); 687} 688 689static caddr_t 690linker_file_lookup_symbol_internal(linker_file_t file, const char *name, 691 int deps) 692{ 693 c_linker_sym_t sym; 694 linker_symval_t symval; 695 caddr_t address; 696 size_t common_size = 0; 697 int i; 698 699 KLD_LOCK_ASSERT(); 700 KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n", 701 file, name, deps)); 702 703 if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) { 704 LINKER_SYMBOL_VALUES(file, sym, &symval); 705 if (symval.value == 0) 706 /* 707 * For commons, first look them up in the 708 * dependencies and only allocate space if not found 709 * there. 710 */ 711 common_size = symval.size; 712 else { 713 KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol" 714 ".value=%p\n", symval.value)); 715 return (symval.value); 716 } 717 } 718 if (deps) { 719 for (i = 0; i < file->ndeps; i++) { 720 address = linker_file_lookup_symbol_internal( 721 file->deps[i], name, 0); 722 if (address) { 723 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 724 " deps value=%p\n", address)); 725 return (address); 726 } 727 } 728 } 729 if (common_size > 0) { 730 /* 731 * This is a common symbol which was not found in the 732 * dependencies. We maintain a simple common symbol table in 733 * the file object. 734 */ 735 struct common_symbol *cp; 736 737 STAILQ_FOREACH(cp, &file->common, link) { 738 if (strcmp(cp->name, name) == 0) { 739 KLD_DPF(SYM, ("linker_file_lookup_symbol:" 740 " old common value=%p\n", cp->address)); 741 return (cp->address); 742 } 743 } 744 /* 745 * Round the symbol size up to align. 746 */ 747 common_size = (common_size + sizeof(int) - 1) & -sizeof(int); 748 cp = malloc(sizeof(struct common_symbol) 749 + common_size + strlen(name) + 1, M_LINKER, 750 M_WAITOK | M_ZERO); 751 cp->address = (caddr_t)(cp + 1); 752 cp->name = cp->address + common_size; 753 strcpy(cp->name, name); 754 bzero(cp->address, common_size); 755 STAILQ_INSERT_TAIL(&file->common, cp, link); 756 757 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common" 758 " value=%p\n", cp->address)); 759 return (cp->address); 760 } 761 KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n")); 762 return (0); 763} 764 765#ifdef DDB 766/* 767 * DDB Helpers. DDB has to look across multiple files with their own symbol 768 * tables and string tables. 769 * 770 * Note that we do not obey list locking protocols here. We really don't need 771 * DDB to hang because somebody's got the lock held. We'll take the chance 772 * that the files list is inconsistant instead. 773 */ 774 775int 776linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym) 777{ 778 linker_file_t lf; 779 780 TAILQ_FOREACH(lf, &linker_files, link) { 781 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0) 782 return (0); 783 } 784 return (ENOENT); 785} 786 787int 788linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp) 789{ 790 linker_file_t lf; 791 c_linker_sym_t best, es; 792 u_long diff, bestdiff, off; 793 794 best = 0; 795 off = (uintptr_t)value; 796 bestdiff = off; 797 TAILQ_FOREACH(lf, &linker_files, link) { 798 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0) 799 continue; 800 if (es != 0 && diff < bestdiff) { 801 best = es; 802 bestdiff = diff; 803 } 804 if (bestdiff == 0) 805 break; 806 } 807 if (best) { 808 *sym = best; 809 *diffp = bestdiff; 810 return (0); 811 } else { 812 *sym = 0; 813 *diffp = off; 814 return (ENOENT); 815 } 816} 817 818int 819linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval) 820{ 821 linker_file_t lf; 822 823 TAILQ_FOREACH(lf, &linker_files, link) { 824 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0) 825 return (0); 826 } 827 return (ENOENT); 828} 829#endif 830 831/* 832 * Syscalls. 833 */ 834/* 835 * MPSAFE 836 */ 837int 838kern_kldload(struct thread *td, const char *file, int *fileid) 839{ 840#ifdef HWPMC_HOOKS 841 struct pmckern_map_in pkm; 842#endif 843 const char *kldname, *modname; 844 linker_file_t lf; 845 int error; 846 847 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 848 return (error); 849 850 if ((error = suser(td)) != 0) 851 return (error); 852 853 /* 854 * If file does not contain a qualified name or any dot in it 855 * (kldname.ko, or kldname.ver.ko) treat it as an interface 856 * name. 857 */ 858 if (index(file, '/') || index(file, '.')) { 859 kldname = file; 860 modname = NULL; 861 } else { 862 kldname = NULL; 863 modname = file; 864 } 865 866 KLD_LOCK(); 867 error = linker_load_module(kldname, modname, NULL, NULL, &lf); 868 if (error) 869 goto unlock; 870#ifdef HWPMC_HOOKS 871 pkm.pm_file = lf->filename; 872 pkm.pm_address = (uintptr_t) lf->address; 873 PMC_CALL_HOOK(td, PMC_FN_KLD_LOAD, (void *) &pkm); 874#endif 875 lf->userrefs++; 876 if (fileid != NULL) 877 *fileid = lf->id; 878unlock: 879 KLD_UNLOCK(); 880 return (error); 881} 882 883int 884kldload(struct thread *td, struct kldload_args *uap) 885{ 886 char *pathname = NULL; 887 int error, fileid; 888 889 td->td_retval[0] = -1; 890 891 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 892 error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL); 893 if (error == 0) { 894 error = kern_kldload(td, pathname, &fileid); 895 if (error == 0) 896 td->td_retval[0] = fileid; 897 } 898 free(pathname, M_TEMP); 899 return (error); 900} 901 902/* 903 * MPSAFE 904 */ 905int 906kern_kldunload(struct thread *td, int fileid, int flags) 907{ 908#ifdef HWPMC_HOOKS 909 struct pmckern_map_out pkm; 910#endif 911 linker_file_t lf; 912 int error = 0; 913 914 if ((error = securelevel_gt(td->td_ucred, 0)) != 0) 915 return (error); 916 917 if ((error = suser(td)) != 0) 918 return (error); 919 920 KLD_LOCK(); 921 lf = linker_find_file_by_id(fileid); 922 if (lf) { 923 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs)); 924 if (lf->userrefs == 0) { 925 /* 926 * XXX: maybe LINKER_UNLOAD_FORCE should override ? 927 */ 928 printf("kldunload: attempt to unload file that was" 929 " loaded by the kernel\n"); 930 error = EBUSY; 931 } else { 932#ifdef HWPMC_HOOKS 933 /* Save data needed by hwpmc(4) before unloading. */ 934 pkm.pm_address = (uintptr_t) lf->address; 935 pkm.pm_size = lf->size; 936#endif 937 lf->userrefs--; 938 error = linker_file_unload(lf, flags); 939 if (error) 940 lf->userrefs++; 941 } 942 } else 943 error = ENOENT; 944 945#ifdef HWPMC_HOOKS 946 if (error == 0) 947 PMC_CALL_HOOK(td, PMC_FN_KLD_UNLOAD, (void *) &pkm); 948#endif 949 KLD_UNLOCK(); 950 return (error); 951} 952 953/* 954 * MPSAFE 955 */ 956int 957kldunload(struct thread *td, struct kldunload_args *uap) 958{ 959 960 return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL)); 961} 962 963/* 964 * MPSAFE 965 */ 966int 967kldunloadf(struct thread *td, struct kldunloadf_args *uap) 968{ 969 970 if (uap->flags != LINKER_UNLOAD_NORMAL && 971 uap->flags != LINKER_UNLOAD_FORCE) 972 return (EINVAL); 973 return (kern_kldunload(td, uap->fileid, uap->flags)); 974} 975 976/* 977 * MPSAFE 978 */ 979int 980kldfind(struct thread *td, struct kldfind_args *uap) 981{ 982 char *pathname; 983 const char *filename; 984 linker_file_t lf; 985 int error; 986 987#ifdef MAC 988 error = mac_check_kld_stat(td->td_ucred); 989 if (error) 990 return (error); 991#endif 992 993 td->td_retval[0] = -1; 994 995 pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 996 if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0) 997 goto out; 998 999 filename = linker_basename(pathname); 1000 KLD_LOCK(); 1001 lf = linker_find_file_by_name(filename); 1002 if (lf) 1003 td->td_retval[0] = lf->id; 1004 else 1005 error = ENOENT; 1006 KLD_UNLOCK(); 1007out: 1008 free(pathname, M_TEMP); 1009 return (error); 1010} 1011 1012/* 1013 * MPSAFE 1014 */ 1015int 1016kldnext(struct thread *td, struct kldnext_args *uap) 1017{ 1018 linker_file_t lf; 1019 int error = 0; 1020 1021#ifdef MAC 1022 error = mac_check_kld_stat(td->td_ucred); 1023 if (error) 1024 return (error); 1025#endif 1026 1027 KLD_LOCK(); 1028 if (uap->fileid == 0) { 1029 if (TAILQ_FIRST(&linker_files)) 1030 td->td_retval[0] = TAILQ_FIRST(&linker_files)->id; 1031 else 1032 td->td_retval[0] = 0; 1033 goto out; 1034 } 1035 lf = linker_find_file_by_id(uap->fileid); 1036 if (lf) { 1037 if (TAILQ_NEXT(lf, link)) 1038 td->td_retval[0] = TAILQ_NEXT(lf, link)->id; 1039 else 1040 td->td_retval[0] = 0; 1041 } else 1042 error = ENOENT; 1043out: 1044 KLD_UNLOCK(); 1045 return (error); 1046} 1047 1048/* 1049 * MPSAFE 1050 */ 1051int 1052kldstat(struct thread *td, struct kldstat_args *uap) 1053{ 1054 struct kld_file_stat stat; 1055 linker_file_t lf; 1056 int error, namelen; 1057 1058 /* 1059 * Check the version of the user's structure. 1060 */ 1061 error = copyin(uap->stat, &stat, sizeof(struct kld_file_stat)); 1062 if (error) 1063 return (error); 1064 if (stat.version != sizeof(struct kld_file_stat)) 1065 return (EINVAL); 1066 1067#ifdef MAC 1068 error = mac_check_kld_stat(td->td_ucred); 1069 if (error) 1070 return (error); 1071#endif 1072 1073 KLD_LOCK(); 1074 lf = linker_find_file_by_id(uap->fileid); 1075 if (lf == NULL) { 1076 KLD_UNLOCK(); 1077 return (ENOENT); 1078 } 1079 1080 namelen = strlen(lf->filename) + 1; 1081 if (namelen > MAXPATHLEN) 1082 namelen = MAXPATHLEN; 1083 bcopy(lf->filename, &stat.name[0], namelen); 1084 stat.refs = lf->refs; 1085 stat.id = lf->id; 1086 stat.address = lf->address; 1087 stat.size = lf->size; 1088 KLD_UNLOCK(); 1089 1090 td->td_retval[0] = 0; 1091 1092 return (copyout(&stat, uap->stat, sizeof(struct kld_file_stat))); 1093} 1094 1095/* 1096 * MPSAFE 1097 */ 1098int 1099kldfirstmod(struct thread *td, struct kldfirstmod_args *uap) 1100{ 1101 linker_file_t lf; 1102 module_t mp; 1103 int error = 0; 1104 1105#ifdef MAC 1106 error = mac_check_kld_stat(td->td_ucred); 1107 if (error) 1108 return (error); 1109#endif 1110 1111 KLD_LOCK(); 1112 lf = linker_find_file_by_id(uap->fileid); 1113 if (lf) { 1114 MOD_SLOCK; 1115 mp = TAILQ_FIRST(&lf->modules); 1116 if (mp != NULL) 1117 td->td_retval[0] = module_getid(mp); 1118 else 1119 td->td_retval[0] = 0; 1120 MOD_SUNLOCK; 1121 } else 1122 error = ENOENT; 1123 KLD_UNLOCK(); 1124 return (error); 1125} 1126 1127/* 1128 * MPSAFE 1129 */ 1130int 1131kldsym(struct thread *td, struct kldsym_args *uap) 1132{ 1133 char *symstr = NULL; 1134 c_linker_sym_t sym; 1135 linker_symval_t symval; 1136 linker_file_t lf; 1137 struct kld_sym_lookup lookup; 1138 int error = 0; 1139 1140#ifdef MAC 1141 error = mac_check_kld_stat(td->td_ucred); 1142 if (error) 1143 return (error); 1144#endif 1145 1146 if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0) 1147 return (error); 1148 if (lookup.version != sizeof(lookup) || 1149 uap->cmd != KLDSYM_LOOKUP) 1150 return (EINVAL); 1151 symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 1152 if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0) 1153 goto out; 1154 KLD_LOCK(); 1155 if (uap->fileid != 0) { 1156 lf = linker_find_file_by_id(uap->fileid); 1157 if (lf == NULL) 1158 error = ENOENT; 1159 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1160 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1161 lookup.symvalue = (uintptr_t) symval.value; 1162 lookup.symsize = symval.size; 1163 error = copyout(&lookup, uap->data, sizeof(lookup)); 1164 } else 1165 error = ENOENT; 1166 } else { 1167 TAILQ_FOREACH(lf, &linker_files, link) { 1168 if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 && 1169 LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) { 1170 lookup.symvalue = (uintptr_t)symval.value; 1171 lookup.symsize = symval.size; 1172 error = copyout(&lookup, uap->data, 1173 sizeof(lookup)); 1174 break; 1175 } 1176 } 1177 if (lf == NULL) 1178 error = ENOENT; 1179 } 1180 KLD_UNLOCK(); 1181out: 1182 free(symstr, M_TEMP); 1183 return (error); 1184} 1185 1186/* 1187 * Preloaded module support 1188 */ 1189 1190static modlist_t 1191modlist_lookup(const char *name, int ver) 1192{ 1193 modlist_t mod; 1194 1195 TAILQ_FOREACH(mod, &found_modules, link) { 1196 if (strcmp(mod->name, name) == 0 && 1197 (ver == 0 || mod->version == ver)) 1198 return (mod); 1199 } 1200 return (NULL); 1201} 1202 1203static modlist_t 1204modlist_lookup2(const char *name, struct mod_depend *verinfo) 1205{ 1206 modlist_t mod, bestmod; 1207 int ver; 1208 1209 if (verinfo == NULL) 1210 return (modlist_lookup(name, 0)); 1211 bestmod = NULL; 1212 TAILQ_FOREACH(mod, &found_modules, link) { 1213 if (strcmp(mod->name, name) != 0) 1214 continue; 1215 ver = mod->version; 1216 if (ver == verinfo->md_ver_preferred) 1217 return (mod); 1218 if (ver >= verinfo->md_ver_minimum && 1219 ver <= verinfo->md_ver_maximum && 1220 (bestmod == NULL || ver > bestmod->version)) 1221 bestmod = mod; 1222 } 1223 return (bestmod); 1224} 1225 1226static modlist_t 1227modlist_newmodule(const char *modname, int version, linker_file_t container) 1228{ 1229 modlist_t mod; 1230 1231 mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO); 1232 if (mod == NULL) 1233 panic("no memory for module list"); 1234 mod->container = container; 1235 mod->name = modname; 1236 mod->version = version; 1237 TAILQ_INSERT_TAIL(&found_modules, mod, link); 1238 return (mod); 1239} 1240 1241static void 1242linker_addmodules(linker_file_t lf, struct mod_metadata **start, 1243 struct mod_metadata **stop, int preload) 1244{ 1245 struct mod_metadata *mp, **mdp; 1246 const char *modname; 1247 int ver; 1248 1249 for (mdp = start; mdp < stop; mdp++) { 1250 mp = *mdp; 1251 if (mp->md_type != MDT_VERSION) 1252 continue; 1253 modname = mp->md_cval; 1254 ver = ((struct mod_version *)mp->md_data)->mv_version; 1255 if (modlist_lookup(modname, ver) != NULL) { 1256 printf("module %s already present!\n", modname); 1257 /* XXX what can we do? this is a build error. :-( */ 1258 continue; 1259 } 1260 modlist_newmodule(modname, ver, lf); 1261 } 1262} 1263 1264static void 1265linker_preload(void *arg) 1266{ 1267 caddr_t modptr; 1268 const char *modname, *nmodname; 1269 char *modtype; 1270 linker_file_t lf; 1271 linker_class_t lc; 1272 int error; 1273 linker_file_list_t loaded_files; 1274 linker_file_list_t depended_files; 1275 struct mod_metadata *mp, *nmp; 1276 struct mod_metadata **start, **stop, **mdp, **nmdp; 1277 struct mod_depend *verinfo; 1278 int nver; 1279 int resolves; 1280 modlist_t mod; 1281 struct sysinit **si_start, **si_stop; 1282 1283 TAILQ_INIT(&loaded_files); 1284 TAILQ_INIT(&depended_files); 1285 TAILQ_INIT(&found_modules); 1286 error = 0; 1287 1288 modptr = NULL; 1289 while ((modptr = preload_search_next_name(modptr)) != NULL) { 1290 modname = (char *)preload_search_info(modptr, MODINFO_NAME); 1291 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE); 1292 if (modname == NULL) { 1293 printf("Preloaded module at %p does not have a" 1294 " name!\n", modptr); 1295 continue; 1296 } 1297 if (modtype == NULL) { 1298 printf("Preloaded module at %p does not have a type!\n", 1299 modptr); 1300 continue; 1301 } 1302 if (bootverbose) 1303 printf("Preloaded %s \"%s\" at %p.\n", modtype, modname, 1304 modptr); 1305 lf = NULL; 1306 TAILQ_FOREACH(lc, &classes, link) { 1307 error = LINKER_LINK_PRELOAD(lc, modname, &lf); 1308 if (!error) 1309 break; 1310 lf = NULL; 1311 } 1312 if (lf) 1313 TAILQ_INSERT_TAIL(&loaded_files, lf, loaded); 1314 } 1315 1316 /* 1317 * First get a list of stuff in the kernel. 1318 */ 1319 if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start, 1320 &stop, NULL) == 0) 1321 linker_addmodules(linker_kernel_file, start, stop, 1); 1322 1323 /* 1324 * this is a once-off kinky bubble sort resolve relocation dependency 1325 * requirements 1326 */ 1327restart: 1328 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1329 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1330 &stop, NULL); 1331 /* 1332 * First, look to see if we would successfully link with this 1333 * stuff. 1334 */ 1335 resolves = 1; /* unless we know otherwise */ 1336 if (!error) { 1337 for (mdp = start; mdp < stop; mdp++) { 1338 mp = *mdp; 1339 if (mp->md_type != MDT_DEPEND) 1340 continue; 1341 modname = mp->md_cval; 1342 verinfo = mp->md_data; 1343 for (nmdp = start; nmdp < stop; nmdp++) { 1344 nmp = *nmdp; 1345 if (nmp->md_type != MDT_VERSION) 1346 continue; 1347 nmodname = nmp->md_cval; 1348 if (strcmp(modname, nmodname) == 0) 1349 break; 1350 } 1351 if (nmdp < stop) /* it's a self reference */ 1352 continue; 1353 1354 /* 1355 * ok, the module isn't here yet, we 1356 * are not finished 1357 */ 1358 if (modlist_lookup2(modname, verinfo) == NULL) 1359 resolves = 0; 1360 } 1361 } 1362 /* 1363 * OK, if we found our modules, we can link. So, "provide" 1364 * the modules inside and add it to the end of the link order 1365 * list. 1366 */ 1367 if (resolves) { 1368 if (!error) { 1369 for (mdp = start; mdp < stop; mdp++) { 1370 mp = *mdp; 1371 if (mp->md_type != MDT_VERSION) 1372 continue; 1373 modname = mp->md_cval; 1374 nver = ((struct mod_version *) 1375 mp->md_data)->mv_version; 1376 if (modlist_lookup(modname, 1377 nver) != NULL) { 1378 printf("module %s already" 1379 " present!\n", modname); 1380 linker_file_unload(lf, 1381 LINKER_UNLOAD_FORCE); 1382 TAILQ_REMOVE(&loaded_files, 1383 lf, loaded); 1384 /* we changed tailq next ptr */ 1385 goto restart; 1386 } 1387 modlist_newmodule(modname, nver, lf); 1388 } 1389 } 1390 TAILQ_REMOVE(&loaded_files, lf, loaded); 1391 TAILQ_INSERT_TAIL(&depended_files, lf, loaded); 1392 /* 1393 * Since we provided modules, we need to restart the 1394 * sort so that the previous files that depend on us 1395 * have a chance. Also, we've busted the tailq next 1396 * pointer with the REMOVE. 1397 */ 1398 goto restart; 1399 } 1400 } 1401 1402 /* 1403 * At this point, we check to see what could not be resolved.. 1404 */ 1405 TAILQ_FOREACH(lf, &loaded_files, loaded) { 1406 printf("KLD file %s is missing dependencies\n", lf->filename); 1407 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1408 TAILQ_REMOVE(&loaded_files, lf, loaded); 1409 } 1410 1411 /* 1412 * We made it. Finish off the linking in the order we determined. 1413 */ 1414 TAILQ_FOREACH(lf, &depended_files, loaded) { 1415 if (linker_kernel_file) { 1416 linker_kernel_file->refs++; 1417 error = linker_file_add_dependency(lf, 1418 linker_kernel_file); 1419 if (error) 1420 panic("cannot add dependency"); 1421 } 1422 lf->userrefs++; /* so we can (try to) kldunload it */ 1423 error = linker_file_lookup_set(lf, MDT_SETNAME, &start, 1424 &stop, NULL); 1425 if (!error) { 1426 for (mdp = start; mdp < stop; mdp++) { 1427 mp = *mdp; 1428 if (mp->md_type != MDT_DEPEND) 1429 continue; 1430 modname = mp->md_cval; 1431 verinfo = mp->md_data; 1432 mod = modlist_lookup2(modname, verinfo); 1433 /* Don't count self-dependencies */ 1434 if (lf == mod->container) 1435 continue; 1436 mod->container->refs++; 1437 error = linker_file_add_dependency(lf, 1438 mod->container); 1439 if (error) 1440 panic("cannot add dependency"); 1441 } 1442 } 1443 /* 1444 * Now do relocation etc using the symbol search paths 1445 * established by the dependencies 1446 */ 1447 error = LINKER_LINK_PRELOAD_FINISH(lf); 1448 if (error) { 1449 printf("KLD file %s - could not finalize loading\n", 1450 lf->filename); 1451 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 1452 continue; 1453 } 1454 linker_file_register_modules(lf); 1455 if (linker_file_lookup_set(lf, "sysinit_set", &si_start, 1456 &si_stop, NULL) == 0) 1457 sysinit_add(si_start, si_stop); 1458 linker_file_register_sysctls(lf); 1459 lf->flags |= LINKER_FILE_LINKED; 1460 } 1461 /* woohoo! we made it! */ 1462} 1463 1464SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0) 1465 1466/* 1467 * Search for a not-loaded module by name. 1468 * 1469 * Modules may be found in the following locations: 1470 * 1471 * - preloaded (result is just the module name) - on disk (result is full path 1472 * to module) 1473 * 1474 * If the module name is qualified in any way (contains path, etc.) the we 1475 * simply return a copy of it. 1476 * 1477 * The search path can be manipulated via sysctl. Note that we use the ';' 1478 * character as a separator to be consistent with the bootloader. 1479 */ 1480 1481static char linker_hintfile[] = "linker.hints"; 1482static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules"; 1483 1484SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path, 1485 sizeof(linker_path), "module load search path"); 1486 1487TUNABLE_STR("module_path", linker_path, sizeof(linker_path)); 1488 1489static char *linker_ext_list[] = { 1490 "", 1491 ".ko", 1492 NULL 1493}; 1494 1495/* 1496 * Check if file actually exists either with or without extension listed in 1497 * the linker_ext_list. (probably should be generic for the rest of the 1498 * kernel) 1499 */ 1500static char * 1501linker_lookup_file(const char *path, int pathlen, const char *name, 1502 int namelen, struct vattr *vap) 1503{ 1504 struct nameidata nd; 1505 struct thread *td = curthread; /* XXX */ 1506 char *result, **cpp, *sep; 1507 int error, len, extlen, reclen, flags, vfslocked; 1508 enum vtype type; 1509 1510 extlen = 0; 1511 for (cpp = linker_ext_list; *cpp; cpp++) { 1512 len = strlen(*cpp); 1513 if (len > extlen) 1514 extlen = len; 1515 } 1516 extlen++; /* trailing '\0' */ 1517 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1518 1519 reclen = pathlen + strlen(sep) + namelen + extlen + 1; 1520 result = malloc(reclen, M_LINKER, M_WAITOK); 1521 for (cpp = linker_ext_list; *cpp; cpp++) { 1522 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep, 1523 namelen, name, *cpp); 1524 /* 1525 * Attempt to open the file, and return the path if 1526 * we succeed and it's a regular file. 1527 */ 1528 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, result, td); 1529 flags = FREAD; 1530 error = vn_open(&nd, &flags, 0, -1); 1531 if (error == 0) { 1532 vfslocked = NDHASGIANT(&nd); 1533 NDFREE(&nd, NDF_ONLY_PNBUF); 1534 type = nd.ni_vp->v_type; 1535 if (vap) 1536 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred, td); 1537 VOP_UNLOCK(nd.ni_vp, 0, td); 1538 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 1539 VFS_UNLOCK_GIANT(vfslocked); 1540 if (type == VREG) 1541 return (result); 1542 } 1543 } 1544 free(result, M_LINKER); 1545 return (NULL); 1546} 1547 1548#define INT_ALIGN(base, ptr) ptr = \ 1549 (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1)) 1550 1551/* 1552 * Lookup KLD which contains requested module in the "linker.hints" file. If 1553 * version specification is available, then try to find the best KLD. 1554 * Otherwise just find the latest one. 1555 */ 1556static char * 1557linker_hints_lookup(const char *path, int pathlen, const char *modname, 1558 int modnamelen, struct mod_depend *verinfo) 1559{ 1560 struct thread *td = curthread; /* XXX */ 1561 struct ucred *cred = td ? td->td_ucred : NULL; 1562 struct nameidata nd; 1563 struct vattr vattr, mattr; 1564 u_char *hints = NULL; 1565 u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep; 1566 int error, ival, bestver, *intp, reclen, found, flags, clen, blen; 1567 int vfslocked = 0; 1568 1569 result = NULL; 1570 bestver = found = 0; 1571 1572 sep = (path[pathlen - 1] != '/') ? "/" : ""; 1573 reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen + 1574 strlen(sep) + 1; 1575 pathbuf = malloc(reclen, M_LINKER, M_WAITOK); 1576 snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep, 1577 linker_hintfile); 1578 1579 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, pathbuf, td); 1580 flags = FREAD; 1581 error = vn_open(&nd, &flags, 0, -1); 1582 if (error) 1583 goto bad; 1584 vfslocked = NDHASGIANT(&nd); 1585 NDFREE(&nd, NDF_ONLY_PNBUF); 1586 if (nd.ni_vp->v_type != VREG) 1587 goto bad; 1588 best = cp = NULL; 1589 error = VOP_GETATTR(nd.ni_vp, &vattr, cred, td); 1590 if (error) 1591 goto bad; 1592 /* 1593 * XXX: we need to limit this number to some reasonable value 1594 */ 1595 if (vattr.va_size > 100 * 1024) { 1596 printf("hints file too large %ld\n", (long)vattr.va_size); 1597 goto bad; 1598 } 1599 hints = malloc(vattr.va_size, M_TEMP, M_WAITOK); 1600 if (hints == NULL) 1601 goto bad; 1602 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0, 1603 UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td); 1604 if (error) 1605 goto bad; 1606 VOP_UNLOCK(nd.ni_vp, 0, td); 1607 vn_close(nd.ni_vp, FREAD, cred, td); 1608 VFS_UNLOCK_GIANT(vfslocked); 1609 nd.ni_vp = NULL; 1610 if (reclen != 0) { 1611 printf("can't read %d\n", reclen); 1612 goto bad; 1613 } 1614 intp = (int *)hints; 1615 ival = *intp++; 1616 if (ival != LINKER_HINTS_VERSION) { 1617 printf("hints file version mismatch %d\n", ival); 1618 goto bad; 1619 } 1620 bufend = hints + vattr.va_size; 1621 recptr = (u_char *)intp; 1622 clen = blen = 0; 1623 while (recptr < bufend && !found) { 1624 intp = (int *)recptr; 1625 reclen = *intp++; 1626 ival = *intp++; 1627 cp = (char *)intp; 1628 switch (ival) { 1629 case MDT_VERSION: 1630 clen = *cp++; 1631 if (clen != modnamelen || bcmp(cp, modname, clen) != 0) 1632 break; 1633 cp += clen; 1634 INT_ALIGN(hints, cp); 1635 ival = *(int *)cp; 1636 cp += sizeof(int); 1637 clen = *cp++; 1638 if (verinfo == NULL || 1639 ival == verinfo->md_ver_preferred) { 1640 found = 1; 1641 break; 1642 } 1643 if (ival >= verinfo->md_ver_minimum && 1644 ival <= verinfo->md_ver_maximum && 1645 ival > bestver) { 1646 bestver = ival; 1647 best = cp; 1648 blen = clen; 1649 } 1650 break; 1651 default: 1652 break; 1653 } 1654 recptr += reclen + sizeof(int); 1655 } 1656 /* 1657 * Finally check if KLD is in the place 1658 */ 1659 if (found) 1660 result = linker_lookup_file(path, pathlen, cp, clen, &mattr); 1661 else if (best) 1662 result = linker_lookup_file(path, pathlen, best, blen, &mattr); 1663 1664 /* 1665 * KLD is newer than hints file. What we should do now? 1666 */ 1667 if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >)) 1668 printf("warning: KLD '%s' is newer than the linker.hints" 1669 " file\n", result); 1670bad: 1671 free(pathbuf, M_LINKER); 1672 if (hints) 1673 free(hints, M_TEMP); 1674 if (nd.ni_vp != NULL) { 1675 VOP_UNLOCK(nd.ni_vp, 0, td); 1676 vn_close(nd.ni_vp, FREAD, cred, td); 1677 VFS_UNLOCK_GIANT(vfslocked); 1678 } 1679 /* 1680 * If nothing found or hints is absent - fallback to the old 1681 * way by using "kldname[.ko]" as module name. 1682 */ 1683 if (!found && !bestver && result == NULL) 1684 result = linker_lookup_file(path, pathlen, modname, 1685 modnamelen, NULL); 1686 return (result); 1687} 1688 1689/* 1690 * Lookup KLD which contains requested module in the all directories. 1691 */ 1692static char * 1693linker_search_module(const char *modname, int modnamelen, 1694 struct mod_depend *verinfo) 1695{ 1696 char *cp, *ep, *result; 1697 1698 /* 1699 * traverse the linker path 1700 */ 1701 for (cp = linker_path; *cp; cp = ep + 1) { 1702 /* find the end of this component */ 1703 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++); 1704 result = linker_hints_lookup(cp, ep - cp, modname, 1705 modnamelen, verinfo); 1706 if (result != NULL) 1707 return (result); 1708 if (*ep == 0) 1709 break; 1710 } 1711 return (NULL); 1712} 1713 1714/* 1715 * Search for module in all directories listed in the linker_path. 1716 */ 1717static char * 1718linker_search_kld(const char *name) 1719{ 1720 char *cp, *ep, *result; 1721 int len; 1722 1723 /* qualified at all? */ 1724 if (index(name, '/')) 1725 return (linker_strdup(name)); 1726 1727 /* traverse the linker path */ 1728 len = strlen(name); 1729 for (ep = linker_path; *ep; ep++) { 1730 cp = ep; 1731 /* find the end of this component */ 1732 for (; *ep != 0 && *ep != ';'; ep++); 1733 result = linker_lookup_file(cp, ep - cp, name, len, NULL); 1734 if (result != NULL) 1735 return (result); 1736 } 1737 return (NULL); 1738} 1739 1740static const char * 1741linker_basename(const char *path) 1742{ 1743 const char *filename; 1744 1745 filename = rindex(path, '/'); 1746 if (filename == NULL) 1747 return path; 1748 if (filename[1]) 1749 filename++; 1750 return (filename); 1751} 1752 1753#ifdef HWPMC_HOOKS 1754 1755struct hwpmc_context { 1756 int nobjects; 1757 int nmappings; 1758 struct pmckern_map_in *kobase; 1759}; 1760 1761static int 1762linker_hwpmc_list_object(linker_file_t lf, void *arg) 1763{ 1764 struct hwpmc_context *hc; 1765 1766 hc = arg; 1767 1768 /* If we run out of mappings, fail. */ 1769 if (hc->nobjects >= hc->nmappings) 1770 return (1); 1771 1772 /* Save the info for this linker file. */ 1773 hc->kobase[hc->nobjects].pm_file = lf->filename; 1774 hc->kobase[hc->nobjects].pm_address = (uintptr_t)lf->address; 1775 hc->nobjects++; 1776 return (0); 1777} 1778 1779/* 1780 * Inform hwpmc about the set of kernel modules currently loaded. 1781 */ 1782void * 1783linker_hwpmc_list_objects(void) 1784{ 1785 struct hwpmc_context hc; 1786 1787 hc.nmappings = 15; /* a reasonable default */ 1788 1789 retry: 1790 /* allocate nmappings+1 entries */ 1791 MALLOC(hc.kobase, struct pmckern_map_in *, 1792 (hc.nmappings + 1) * sizeof(struct pmckern_map_in), M_LINKER, 1793 M_WAITOK | M_ZERO); 1794 1795 hc.nobjects = 0; 1796 if (linker_file_foreach(linker_hwpmc_list_object, &hc) != 0) { 1797 hc.nmappings = hc.nobjects; 1798 FREE(hc.kobase, M_LINKER); 1799 goto retry; 1800 } 1801 1802 KASSERT(hc.nobjects > 0, ("linker_hpwmc_list_objects: no kernel " 1803 "objects?")); 1804 1805 /* The last entry of the malloced area comprises of all zeros. */ 1806 KASSERT(hc.kobase[hc.nobjects].pm_file == NULL, 1807 ("linker_hwpmc_list_objects: last object not NULL")); 1808 1809 return ((void *)hc.kobase); 1810} 1811#endif 1812 1813/* 1814 * Find a file which contains given module and load it, if "parent" is not 1815 * NULL, register a reference to it. 1816 */ 1817static int 1818linker_load_module(const char *kldname, const char *modname, 1819 struct linker_file *parent, struct mod_depend *verinfo, 1820 struct linker_file **lfpp) 1821{ 1822 linker_file_t lfdep; 1823 const char *filename; 1824 char *pathname; 1825 int error; 1826 1827 KLD_LOCK_ASSERT(); 1828 if (modname == NULL) { 1829 /* 1830 * We have to load KLD 1831 */ 1832 KASSERT(verinfo == NULL, ("linker_load_module: verinfo" 1833 " is not NULL")); 1834 pathname = linker_search_kld(kldname); 1835 } else { 1836 if (modlist_lookup2(modname, verinfo) != NULL) 1837 return (EEXIST); 1838 if (kldname != NULL) 1839 pathname = linker_strdup(kldname); 1840 else if (rootvnode == NULL) 1841 pathname = NULL; 1842 else 1843 /* 1844 * Need to find a KLD with required module 1845 */ 1846 pathname = linker_search_module(modname, 1847 strlen(modname), verinfo); 1848 } 1849 if (pathname == NULL) 1850 return (ENOENT); 1851 1852 /* 1853 * Can't load more than one file with the same basename XXX: 1854 * Actually it should be possible to have multiple KLDs with 1855 * the same basename but different path because they can 1856 * provide different versions of the same modules. 1857 */ 1858 filename = linker_basename(pathname); 1859 if (linker_find_file_by_name(filename)) 1860 error = EEXIST; 1861 else do { 1862 error = linker_load_file(pathname, &lfdep); 1863 if (error) 1864 break; 1865 if (modname && verinfo && 1866 modlist_lookup2(modname, verinfo) == NULL) { 1867 linker_file_unload(lfdep, LINKER_UNLOAD_FORCE); 1868 error = ENOENT; 1869 break; 1870 } 1871 if (parent) { 1872 error = linker_file_add_dependency(parent, lfdep); 1873 if (error) 1874 break; 1875 } 1876 if (lfpp) 1877 *lfpp = lfdep; 1878 } while (0); 1879 free(pathname, M_LINKER); 1880 return (error); 1881} 1882 1883/* 1884 * This routine is responsible for finding dependencies of userland initiated 1885 * kldload(2)'s of files. 1886 */ 1887int 1888linker_load_dependencies(linker_file_t lf) 1889{ 1890 linker_file_t lfdep; 1891 struct mod_metadata **start, **stop, **mdp, **nmdp; 1892 struct mod_metadata *mp, *nmp; 1893 struct mod_depend *verinfo; 1894 modlist_t mod; 1895 const char *modname, *nmodname; 1896 int ver, error = 0, count; 1897 1898 /* 1899 * All files are dependant on /kernel. 1900 */ 1901 KLD_LOCK_ASSERT(); 1902 if (linker_kernel_file) { 1903 linker_kernel_file->refs++; 1904 error = linker_file_add_dependency(lf, linker_kernel_file); 1905 if (error) 1906 return (error); 1907 } 1908 if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop, 1909 &count) != 0) 1910 return (0); 1911 for (mdp = start; mdp < stop; mdp++) { 1912 mp = *mdp; 1913 if (mp->md_type != MDT_VERSION) 1914 continue; 1915 modname = mp->md_cval; 1916 ver = ((struct mod_version *)mp->md_data)->mv_version; 1917 mod = modlist_lookup(modname, ver); 1918 if (mod != NULL) { 1919 printf("interface %s.%d already present in the KLD" 1920 " '%s'!\n", modname, ver, 1921 mod->container->filename); 1922 return (EEXIST); 1923 } 1924 } 1925 1926 for (mdp = start; mdp < stop; mdp++) { 1927 mp = *mdp; 1928 if (mp->md_type != MDT_DEPEND) 1929 continue; 1930 modname = mp->md_cval; 1931 verinfo = mp->md_data; 1932 nmodname = NULL; 1933 for (nmdp = start; nmdp < stop; nmdp++) { 1934 nmp = *nmdp; 1935 if (nmp->md_type != MDT_VERSION) 1936 continue; 1937 nmodname = nmp->md_cval; 1938 if (strcmp(modname, nmodname) == 0) 1939 break; 1940 } 1941 if (nmdp < stop)/* early exit, it's a self reference */ 1942 continue; 1943 mod = modlist_lookup2(modname, verinfo); 1944 if (mod) { /* woohoo, it's loaded already */ 1945 lfdep = mod->container; 1946 lfdep->refs++; 1947 error = linker_file_add_dependency(lf, lfdep); 1948 if (error) 1949 break; 1950 continue; 1951 } 1952 error = linker_load_module(NULL, modname, lf, verinfo, NULL); 1953 if (error) { 1954 printf("KLD %s: depends on %s - not available\n", 1955 lf->filename, modname); 1956 break; 1957 } 1958 } 1959 1960 if (error) 1961 return (error); 1962 linker_addmodules(lf, start, stop, 0); 1963 return (error); 1964} 1965 1966static int 1967sysctl_kern_function_list_iterate(const char *name, void *opaque) 1968{ 1969 struct sysctl_req *req; 1970 1971 req = opaque; 1972 return (SYSCTL_OUT(req, name, strlen(name) + 1)); 1973} 1974 1975/* 1976 * Export a nul-separated, double-nul-terminated list of all function names 1977 * in the kernel. 1978 */ 1979static int 1980sysctl_kern_function_list(SYSCTL_HANDLER_ARGS) 1981{ 1982 linker_file_t lf; 1983 int error; 1984 1985#ifdef MAC 1986 error = mac_check_kld_stat(req->td->td_ucred); 1987 if (error) 1988 return (error); 1989#endif 1990 error = sysctl_wire_old_buffer(req, 0); 1991 if (error != 0) 1992 return (error); 1993 KLD_LOCK(); 1994 TAILQ_FOREACH(lf, &linker_files, link) { 1995 error = LINKER_EACH_FUNCTION_NAME(lf, 1996 sysctl_kern_function_list_iterate, req); 1997 if (error) { 1998 KLD_UNLOCK(); 1999 return (error); 2000 } 2001 } 2002 KLD_UNLOCK(); 2003 return (SYSCTL_OUT(req, "", 1)); 2004} 2005 2006SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLFLAG_RD, 2007 NULL, 0, sysctl_kern_function_list, "", "kernel function list"); 2008